Community
OpenEnergyMonitor

OpenEnergyMonitor Community

Can the emonPi read the pulses from a reed switch? (idea for domestic cold water monitoring)

Tags: #<Tag:0x00007f88c1e8c2f8>

Hi all,

Bit of a weird one. I am thinking about monitoring the domestic cold water usage in the home per second and to send that to the emonPi. The idea would be to fit a cheap flow meter with a reed switch straight after the cockstop tap, and have a wire going from the flow meter to the emonPi. I would then get the emonPi to convert pulses into flow per second (or per 5 seconds if thats the highest resolution feed you can have).

However, this idea is dead if the emonPi is not set up for this. So, can the emonPi read pulses on any of its inputs, and can it convert that into a feed data?

Thanks for any help.
Steffan

No, obviously only on the pulse input. The others are for analogue quantities on the voltage & current inputs, or serial digital data on the OneWire input.

Did you look at the entry for the emonPi in the Wiki?

https://wiki.openenergymonitor.org/index.php/EmonPi

ah that is handy. So the EmonPi has a pulse counter input and it’s already soldered to the RJ45 input on the EmonPi. The software is ready to monitor data from this input but it needs scaling to match pulses to actual flow.

So, in practice, connect wires 5 (GND) and 6 (IRQ1) across the reed switch for volt-free pulse counting and plug in the RJ45 head into the emonPi.
https://wiki.openenergymonitor.org/index.php/EmonPi#Pulse_Counting